1. Field of the Invention
This invention relates generally to processing e-mail, and more particularly to filtering and providing flexible access to e-mail.
2. Description of the Related Art
Electronic mail (e-mail) is now widely used for sending and receiving messages, for both personal and business uses. As the usage of e-mail has increased, so has the use of the medium to distribute unsolicited marketing messages. These messages are typically sent to numerous users, sometimes millions of users, in the hope that even a small percentage of the recipients will respond. The messages are often referred to as spam.
The proliferation of spam has various drawbacks. It is often annoying to receive even a limited number of unsolicited offers, as it is time consuming to review e-mail messages to determine that they are such, and then delete them. An e-mail account can be so afflicted with a spam problem that it can be rendered useless—an account left idle for a seemingly brief period may accumulate so many unwanted messages that it becomes too burdensome to review and remove them.
The unsolicited messages also consume processing and storage resources. Individuals and businesses have finite computing resources, and spam has increasingly strained them. For individual accounts, this may lead to situations where an e-mail account with a limited amount of capacity quickly reaches that capacity and becomes useless. For businesses, the problem multiplies based upon the number of employees on the e-mail system. Businesses are forced to purchase and manage more computer resources than are necessary for legitimate business purposes.
One solution to the growing spam problem has been the introduction of filtering systems that seek to automatically screen incoming mail. These filtering systems can be integrated into a mail server that is accessed by e-mail client devices. Filtering may also be provided by proxy servers or the like that handle incoming mail and engage in the filtering process prior to passing along e-mails to the mail server. With many of these systems, a recipient will receive approved e-mail in the usual fashion, and will navigate to interfaces managed by the filtering server to approve or dispose of questionable messages. The user will often be invited to engage in this review by a reminder e-mail sent through the original system, indicating that withheld messages are available for review.
While such filtering has been moderately effective at screening spam, the filtering process can be over and under-inclusive at times. Additionally, configuring filter settings can be time consuming for the user. Numerous categories of filtering have been developed. One such category is referred to as “black listing.” According to this technique, messages from senders known to be distributors of unsolicited e-mails are automatically designated as undesirable, and are not passed along to the recipient as legitimate e-mail. Black list services automatically update the black list, and in some systems a user may also add names to the black list. While these techniques work well, they are often circumvented by repeated changes in originating addresses.
Heuristic techniques apply rules to characteristics found in analyzed messages to determine whether they are spam. Instances or combinations of particular terms in an e-mail and other criteria often result in a positive indication that the message is spam. These techniques are also helpful but can result in “false positives”—instances where e-mails are wrongly determined to be spam.
To help alleviate the false positive problem, “white list” techniques have been developed. These schemes maintain a list of senders that are known to be approved by the sender. This helps minimize the false positives problem somewhat, but also burdens the user with having to maintain the white list. Users quickly tire to the addition of senders to the white list. To help automate the maintenance of the white list, a confirmation technique has been used. There, a sender is sent a return e-mail requesting a second confirmation message from the sender before allowing message delivery. The rationale behind this scheme is that many automated spamming processes will not respond with a confirmation message. However, many legitimate senders also do not respond to the request for confirmation. Thus, with various conventional white list techniques, there are often messages that are erroneously determined to be unsolicited spam.
Another problem with e-mail management, particularly with system that implement an Internet based mail server that is variously accessible by the user, is accommodating access to e-mails that have already been downloaded and deleted from a mail server pursuant to access by the user. This may arise in various circumstances, such as where the user accesses the message from the office, then realizes that they may want to access the email from another location at a later time. While the message could simply be manually forwarded by the user to their own e-mail address, this can be cumbersome, can be hampered by errors in entering the e-mail address, and does not provide an e-mail that appears to be from the original sender. This is also an issue where the user is managing e-mail in conjunction with an e-mail filtering system, where the user may be unsure which e-mails are being retained and which are to be deleted.
Thus, while conventional e-mail filtering options have helped alleviate some problems related to unsolicited e-mail management, there remains a need for a system that allows the user to easily designate e-mails as desirable and simultaneously avoids false determinations that e-mails are not desirable. Additionally, there remains a need for an e-mail access system that allows e-mails to be downloaded to a client machine and subsequently returned to a mail server as though they had not been downloaded, and a need for a system that accommodates coherent management of e-mail.